Stability Indicating HPLC Method for Simultaneous Determination of Diacerein and Aceclofenac

A simple, specific, accurate and stability-indicating reversed phase high performance liquid chromatographic method was developed for the simultaneous determination of diacerein and aceclofenac, using a RP-18 column and a mobile phase composed of water: acetonitrile (45: 55, v/v) pH 2.4 adjusted with o-phosphoric acid. The retention time of diacerein and aceclofenac were found to be 5.9 min and 14.2 min, respectively. Linearity was established for diacerein and aceclofenac in the range of 1–10 μg/ml and 2–20 μg/ml, respectively. The percentage recoveries of diacerein and aceclofenac were found to be in the range of 98.90–100.05% and 99.60–100.68%, respectively. Both the drugs were subjected to acid, alkali and neutral hydrolysis, oxidation, dry heat, and photolytic degradation. The degradation studies indicated diacerein to be susceptible to H2O2, dry heat, acid, alkaline and neutral hydrolysis, while aceclofenac showed degradation in acid and alkali.The degradation products of diacerein and aceclofenac were well resolved from the pure drugs with significant differences in the retention time values. This method can be successfully employed for simultaneous quantitative analysis of diacerein and aceclofenac in bulk drugs and formulations.